#include<iostream>

using namespace std;


//class B;
//class A
//{
//public:
//	friend void test_friend(const A& a, const B& b);
//public:
//	int _num = 10;
//};
//
//class B
//{
//public:
//	friend void test_friend(const A& a, const B& b);
//protected:
//	string _name = "li";
//};
//
//void test_friend(const A& a, const B& b)
//{
//	cout << a._num << endl;
//	cout << b._name << endl;
//}


class A
{
public:

protected:
	int _num = 10;

public:
	static int _count;
};

int A::_count = 0;

class B
{
public:

protected:
	string _name = "li";
};

int main()
{

}